###################################################
### chunk number 1: 
###################################################
library(grDevices)
library(grid)
ps.options(pointsize=12)
options(width=60)



###################################################
### chunk number 2: prim1
###################################################
pushViewport(viewport(layout=grid.layout(1, 2,
  widths=unit(c(1, 1), c("inches", "null")))))
grid.rect(gp=gpar(col="grey"))
pushViewport(viewport(layout.pos.col=1))
grid.text(c("segments", "text", "lines", "rectangles",
  "circles", "points"),
  x=1, just="right", y=c(0.75, 6:2/10), gp=gpar(col="grey"))
popViewport()
pushViewport(viewport(layout.pos.col=2))
x <- 1:7/8
x[4] <- NA
grid.lines(x, 0.5)
grid.text(letters[1:5], x, 0.6)
grid.segments(x, 0.7, x, 0.8)
grid.points(x, rep(0.2, 7))
grid.rect(x, 0.4, 0.02, 0.02)
grid.circle(x, 0.3, 0.02)
grid.text("NA", 0.5, 2:8/10, gp=gpar(col="grey"))
popViewport(2)



###################################################
### chunk number 3: prim2
###################################################
n <- 7
primtest2 <- function(nas, na) {
  t <- seq(0, 2*pi, length=n+1)[-(n+1)]
  y <- 0.5 + 0.4*sin(t)
  x <- 0.5 + 0.4*cos(t)
  if (any(nas))
    grid.text(paste("NA", (1:n)[nas], sep=""),
              x[nas], y[nas], gp=gpar(col="grey"))
  x[nas] <- na
  y[nas] <- na
  grid.move.to(x[1], y[1])
  for (i in 2:n) {
    grid.line.to(x[i], y[i], gp=gpar(lty="dashed", lwd=5))
  }
  grid.polygon(x, y, gp=gpar(fill="grey", col=NULL))
  grid.lines(x, y, arrow=arrow())
}
celltest <- function(r, c, nas, na) {
  pushViewport(viewport(layout.pos.col=c,
                        layout.pos.row=r))
  primtest2(nas, na)
  grid.rect(gp=gpar(col="grey"))
  popViewport()
}
cellnas <- function(i) {
  temp <- rep(FALSE, n)
  temp[i] <- TRUE
  temp[n-3+i] <- TRUE
  temp
}
pushViewport(viewport(layout=grid.layout(2, 2)))
celltest(1, 1, rep(FALSE, n), NA)
celltest(1, 2, cellnas(1), NA)
celltest(2, 1, cellnas(2), NA)
celltest(2, 2, cellnas(3), NA)
popViewport()




###################################################
### chunk number 4:  eval=FALSE
###################################################
## grid.newpage()
## 


